Trammel-head.



A. BJORKLUND.

TRAMMEL HEAD.

APPLICATION FILED 0011.3, 1910.

1,007,424. Patented 001. 31, 1911.

ARVID BJORKLUND, OF MINNEAPOLIS, MINNESOTA.

TRAMMEL-I-IEAD.

Specification of Letters Patent.

Patented Oct. 31, 1911.

Application filed October 3, 1910. Serial No. 585,093.

To all whom it may concern:

Be it known that I, ARvn) BJORKLUND, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Tramniel- Heads; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention has for its object to provide an improved trammel head and to this end the invention consists of the novel devices and construction of parts hereinafter described and defined in the claims.

In the accompanying drawings which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings: Figure 1 is a view in side elevation with some parts broken away and with some parts sectioned, showing a trammel head designed in accordance with my invention and applied to the trammel bar; and, Fig. 2 is a transverse vertical section taken on the line m? m of Fig. l.

The trammel bar is indicated by the numeral 1.

The pin trammel point is indicated by the numeral 2. The pin 2 is provided with a head of novel construction and which, in its preferred form, comprises an approximately U-shaped flat spring member 3 intermediately secured to the large end of the pin 2 and provided in its prongs with rectangular openings at through which the trammel bar 1 is adapted to be passed. In the approximately U-shaped member 3 is a central bearing alforded, as shown, by an approximately seini-cylindrical block 5. The upper and central portion of this bearing block 5 engages the lower edge of the trammel bar 1, while the upper portions of the slots 4 are pressed against the upper edge of the trammel bar by the spring tension of the prongs of the said U-shaped member 3. The prongs of the said member 3 tend to spring apart and they are of such length that their lower extremities will not engage with the lower edge of the bar 1. This leaves the bar 3 always clamped at three points, to-wit, the

points a, a, and b. This means of clamping the trammel bar securely holds the head wherever set. Then it is desired to adjust the trammel point on the bar, it is only necessary to press slightly toward each other the upper extremities of the prongs of the U-shaped member 3. This will afiord clearance, or in other words, will release the spring prongs from clamping engagement of the bar so that any adjustment of the trammel point may be easily accomplished. In practice, of course, a pair of trammel points or pins will be applied on the trammel bars. The central bearing at b may be afiorded in various different ways, but it is essential that this bearing point Z) be located below and between the clamping points a so that the three-point engagement with the trammel bar will be accomplished.

The device described is of small cost and at the same time, it is highly eflicient for the purposes had in view.

VVha-t I claim is:

1. A. trammel pin having at its head end a central bearing for engagement at one edge of a trammel bar and provided on each side thereof with spring prongs that are perforated so as to pass the trammel bar therethrough, the said spring prongs being formed from a single piece of spring metal, substantially as described.

2. The combination with a trammel bar, of a trammel pin having at its head end a central bearing for engagement with the lower edge of said bar, and provided with upward diverging outwardly pressed and united spring prongs having perforations through which the trammel bar is passed, the perforations in the said prongs being of such length that the upper edge of the trammel bar will be engaged by the upper extremities of said perforations, with clearance between the lower extremities of said slots and the lower edge of said bar, substantially as described.

In testimony whereof I afiix my signature in presence of two witnesses.

ARVID BJORKLUND.

Witnesses:

HARRY D. KILGORE, BERNIOE G. I/VHEELER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

